Best practice for gas line under ground

[parkertj]

I will need to run a 3/4" line from the meter to a new tankless water heater in a new attached garage, about a 30 foot run under ground. What is best practice for piping and how do I enter the new building?
Thanks.

[jproffer]

Question 1) Here code says gas line has to be black pipe, period. Nothing else.

Q2) Hammer drill, patience, and a week of walking around shaking afterwards and you shouldn't have any trouble. :D


EDIT: BTW, that's not a regular "go to wallyworld and buy one" hammer drill. You should probably rent this, not buy it. Very big, very expensive, but very powerful too.

[Sparks]

You can't directly bury black pipe. It would need to be sleeved if underground or a suitable flex pipe rated for direct burial, there are a few brands so check your supply houses for specifics. I wouldn't think you would need to penetrate the foundation or slab of the building but check with your local inspector and see what is required for your area. You may just be able to enter through a stud wall. In my opinion, always check with the authority having jurisdiction, get a permit and have the work inspected when working with gas piping. Why do it any other way, the cost is minimal and it's insuring the job is done correctly and to code. Your insurance company will also appreciate it and it will keep you out of trouble in the future should something go wrong. Either that, or hire a licensed contractor to perform the work, and make sure he's insured.

[kadoka]

They use plastic flex pipe here for underground gas lines here. Just had a propane tank installed to the new house. 18" deep and it was a yellow plastic pipe. Can't tell you for sure what it was for a pipe.

[rabadger]

The gas company will tell you the type of plastic that should be used. It has to be one continuous run with the black to plastic adaptors out of the ground. When running the plastic gas line wrap it with a tracer wire so it can be located at a later date.

Now for the good question. How did you know you need 3/4"? Did you account for the BTU of the heater, run distance amount of elbows, and pressure drop? Or did you just see a 3/4" tapping on the heater and figure that was good enough?

[Bakerdog]

well i sure feel lucky that my gas company relocated our line for free. of course, they used something they called a mouse that used pressurized air to bore the hole for runing the line underground. So they only needed to dig holes where they were connecting the pipe. it took them about an hour to move about 50' of the pipe.